Watashi wa Gurēsu desu. Yoroshiku onegaishimasu!". If you'd like to introduce yourself in a more formal way, you have to say: "konnichiwa! Hajimemashite. Watakushi wa Gurēsu to moushimasu. Kyou wa yoroshiku onegai itashimasu!". With "Watakushi" rather than "Watashi", "to moushimasu" ...
Japanese transcript (Romanji) hajimemashite, watashi wa mai desu. soshite kyoo wa watashi no machi ni tsui te hanashimasu. hanoi desu. watashi wa nagaima hanoi